By detecting a voltage drop in resistor connected in series with the battery, we can measure the current flowing in or out of the battery. A simple differential amplifier do that, but we need both positive supply and negative supply to sense the current in both direction, the current when charging and discharging the battery. We can use a single supply by separating the circuit for each direction like shown in this circuit:
[Source: Linear Technology Application Notes]
Possibly Related Articles:
- Single Transistor Lead Acid Battery Monitor
We can make a very simple battery monitor using a dual-colour LED and a few additional components. When the red and green LEDs are illuminated, the LED produces orange. The... - Two Transistors Lead Acid Battery Monitor
Three separated LEDs is used on this battery monitor circuit. For red LED, it’s turn on from 6v to below 11v and turns off above 11v. For the orange LED,... - Simple 555 Switching Circuit Provides Negative Supply from Single Positive Supply
If you need a negative supply for op-amp or just need negative bias voltage while operating from a single supply voltage (for battery operation for example), this circuit helps providing... - Current Monitor
On the circuit diagram, R1 is used to senses current flow of a power supply. We could use JFET as a buffer because Id=Is, therefore the power supply current flow... - Single Chip Thermocouple 4-20mA Current Loop Transmiter Circuit
Thermocouples give many benefits compared to thermistor/RTD (Resistance Temperature Devices). Some advantages of thermocouple are their wider temperature range, their reliability, and their consistency over long period of time. In...
| 
